Methyprylon (Noludar) was a sedative of the piperidinedione derivative family developed by Hoffmann-La Roche.[1]
This medicine was used for treating insomnia, but is now rarely used as it has been replaced by newer drugs with fewer side effects, such as benzodiazepines.[2]
Methyprylon was withdrawn from the US market in June 1965 and the Canadian market in September 1990.
Some other trade names are Noctan and Dimerin.

A case report found that the pharmacokinetics of methyprylon were not concentration dependent in an overdose case; explanations included saturation or inhibition of metabolic pathways. The generally accepted half-life for a therapeutic dose was not found appropriate in intoxicated patients and would underestimate the time required to reach a safe concentration of the drug.[4]